Thermostatic drain valve



Aug- 30,v 1955 w. F. BORGERD 2,716,418

'lHEm/IOSTATIC DRAIN VALVE Filed Dec. 29, 195o 2 sheets-sheet 1 F75-721i 84 .98 J1 v6 27 i5 2 4 f l 4554 331) $5 r4@ |J\ 444% /f// THERMOSTATIC DRAIN VALVE William F. Borgerd, Evansville, Ind., assignor to International Harvester Company, a corporation of New Jersey Application December 29, 1950, Serial No. 203,452

4 claims. (c1. 137-61) This invention relates generally to a thermostatic drain.

valve and more particularly to a valve which will automatically drain the liquid from a cooling system when the system is subjected to freezing conditions.

The present invention provides a valve which is particularly adaptable for draining water from a water cooled condenser of an air conditioning system. During sudden periods of unusually cold weather, tremendous damage is often done to water cooled condensers since the air conditioningsystems are ordinarily placed in enclosed rooms which are heated only by heat leakage from adjacent heated rooms. The temperature of the condenser will be lowered below the freezing point f water during such cold Weather, which results in the freezing of the water in the condenser. As the water freezes, it expands and bursts the condenser. Accidents of this kind are quite common in business buildings, especially if the cold weather occurs on a weekend when attendants are absent from the building. When the condenser has burst, water runs all through the refrigeration system and the job of cleaning the system costs nearly as much as a new condensing unit because of the repeated purging with refrigerant thatis necessary andV the multitude of chemical dryers that must be used. By providing automatic means for draining the condenser, serious damage to the air conditioning system-will be prevented.

One object of the present invention is to provide a drain valve which automatically cuts off the supply of cooling water to a water cooled condenser and completely drains water from the condenser when the temperature of the condenser approaches the freezing point of water.

Another object of the invention is to provide a drain valve with thermostatic means for operating the valve in response to ambient temperatures. l

A further object of the invention is to provide a thermostatic drain valve which may be manually reset and which may be easily checked to determine if it is in proper operating condition. f

Another object of the invention is to provide a thermostatic drain valve with signal means for warning an operator when the valve has moved to drain position.

Another object of the invention is to provide a cooling system with a drain valve which will positively and rapidly operate to drain the system when the system is subjected to freezing temperatures.

With the above and other objects in view the invention consists in certain novel details of construction and combinations of parts hereinafter fully described and claimed, it being understood that various modifications may be resorted to within the scope of the appended claims without departing from the spirit or sacrificing any of the advantages of the invention.

ln the accompanying drawings forming part of this specification:

Fig. l is a horizontal sectional view of the drain valve taken on line 1--1 of Fig. 2.

e CC.

Fig. 2 is a diagrammatic view of a refrigeration system with an enlarged side elevational view of the drain valve.v

Fig. 3 is a diagram of the electric circuit for the refrigeration system.

Fig. 4 is a vertical sectional view of the valve taken on line 4-4 of Fig. l.

Fig. 5 is a vertical sectional View of the valve showing the movable parts in drainage position.

Referring specifically to the drawings, numeral r designates generally a drain valve which is connected to the Water inlet 11vof a water cooled condenser 12 by hose 13. The water outlet 14 of condenser 12 is connected to a suitable waste pipe by hose 15. The condenser 12 is a member of a refrigeration system comprising motor-compressor unit 16 and evaporator 17.

After the refrigerant is compressed by motor-compressor fili unit 16, it flows through conduit 18 into a series of ytubes in condenser 12 where it is cooled by the water flowing into water inlet 11, around the tubes and out the water throughconduit 19 into expansion valve 20, then through f: ,i conduit 21 into evaporator 17. The air to be conditioned is passed over the evaporator and is cooledl by the refrigerant passing therethrough. From-the evaporator 17,

the refrigerant returns to the motor-compressor unit 16 through conduit 22 and repeats the cycle.

The drain valve 10 comprises a generally tubular shaped valve body 23 provided with three interconnecting cylindrical shaped chambers 24, 25 and 26 which extend through the central portion of the body. These chambers will hereinafter be referred to as inlet chamber 24, outlet chamber 25 and power chamber 26. One end of inlet chamber 24 is internally threaded into which` an externally threaded nipple 27 is threaded. Valve :t5 body 23 is provided with an outlet nozzle 28 having a passageway 29 which extends into communication with 31.. inlet chamber 24. A drain nozzle 30 is provided on the lower part of valve body 23 having a passageway 31 which extends into outlet chamber 25. An annular 4.o shoulder 32 surrounds a valve port 97 and provides a valve seat 33 between valve chamber 24 yand outlet chamber 25. .Nipple 27 is provided with an annular shoulder 34 which surrounds valve port 98 and forms a second valve seat 35. A valve member or disc 36 is secured to one end of a valve stem 37 and positioned Within valve chamber 24. Secured in an annular groove 99 in @o valve member 36 is a serrated ring 38 which helps to support the end of valve `stem 37 and insures concentric seating lofvvalve member 36 againstvalve seats 33 and 35.

Valve stem 37 extends through outlet chamber 25 into power chamber 26. Between these chambers is a wall iii; member 39 which is secured in valve body 23 by a snap ring 41 and is provided with a central opening 40 through which the valve stem 37 extends in sliding relationship thereto. vA compressible coiled spring 42 encircles valve ifi stem 37 with one end abutting wall member 39 and the E other end abutting an annular shoulder 43 formed on valve stern 37. A hollow cylindrical shapedA piston 44V is fitted in power chamber 26 in sliding relationship thereto so that it is adapted for reciprocating movement there- 1.1: opening through which the Valve stem 37 extends.

portion of piston 44 is provided with a slot 47. Slidably received within piston 44 is a cylindrical `shaped sleeve rf; 48 having an internal bore 49 extending therethrough.

The end of valve stem 37 extends into bore 49 and is xedly secured to the sleeve 48 by pin 50. `A horizon- '$0 tally extending cross pinSl is tixedly secured to piston 44. Slots 52 and 53 are provided in valve body 23 through which the ends of the cross pin 51 extend,

outlet 14. The refrigerant fiows from condenser 12` Sleeve .48 is provided with slots .54 and 55 through which the pin 51 extends. The slots 54 and 55 are made a length which is approximately twice the diameter of pin 511, whereas -the length of slots 52 and 53 is considerably greater.l A vcompressible .coiled spring 56 encircles valve stem 37 withone end abutting the closed end 45 of piston 44 and the other end abutting the forward end of sleeve 48.

A portion of valve body 23 is cut away to provide an opening 57 which-communicates with the top portion of power chamber 26. An opstanding projection 58 is formed as part of val-ve body 23 along Vthe forward edge of opening I'7. Pivotally secured to projection 58 by pivot pin 59 is a trigger member 60 having a Vsubstantially horizontally extending handle 61 and an upstanding leg 62. A bottom -port-ion 63 of handle 61 extends into opening V57 vand is provided with a notch 64 which iits over the beveled edge y46 of piston 44. An internally threaded opening 65 is provided in leg 62 in which an vexternally vthreaded adjusting screw 66 is secured. One end of vadjusting screw 66 is provided with a knob 67 vwhich may be used -to set the screw and a nut 68 is provided vfor lholding the s crew securely in place after it is properly set. An indicator lpin 69 is secured below knob 67 which aids the operator in adjusting the knob to a proper position.

A lthermostatic element 70 is provided for forcing trig ger member `62 about pivot pin 59. The thermostatic element is provided with a cup portion 71 which is secured in recess 72 formed in valve body 23 and abuts against an `anvil pin 73 which is secured in valve body 23. A plunger 74 extends from the thermostatic element '70 with the outer end secured in a recess 75 formed in set screw 66. The cup portion 71 is iilled with an expansible-contractible substance which moves plunger 74 when the cup portion is subjected .to varying temperatures.

A rubber hose 13 connects the outlet ynozzle 28 to condenser `inlet 11 and rubber hose 76 connects nipple 27 to a suitable water supply. Drain nozzle 30 is connected to a suitable waste pipe `by hose 77. The drain valve is positioned adjacent the condenser 12 so `that they will both vbe subjected to the same ambient temperature. When .the .refrigeration system is operating under normal conditions, the .drain valve parts will be positioned as shown .in Figs. l and 4 of the drawing. Trigger member 60 will be .forced clockwise .by thermostatic element 70 with notch .64 .tittingover vbeveled edge 46 of .piston .44. Spring 5 6 is stiffer than spring v42 so that sleeve 48 is forced .to .the right .by spring 56. Since valve stem 37 is secured `to the sleeve 48 by pin 50, the valve stem will be Amoved to the right until valve member 36 is in contact .with :valve seat 33. This opens valve Yseat 35 so that cooling water `will pass through nipple 27, vvalve chamber 24.l Ppassageway 29, and hose 13 into condenser 12. The .thermostatic element 70 and set screw 66 are adjusted so .that trigger member .60 -will be retained with notch .64 engaging beveled edge v46 of piston 44 as long as ,the 4temperature of thermostat-ic velement does not approach the freezing point of water. With the -drain valve parts in :this position, the condenser 12 will be properly cooled by ,the cooling water. Spring 56 is `strong enough to .overcome spring 42 so that -the valve member 36 is securelyfseated against valve-seat 33 which prevents water from .running .into -outlet chamber 25. The cross pin 51 ,is positioned proximate the rear edges -of Vthe slots 52,513.54, and 55.

When the temperature ofthe air surrounding condenser 12 andthe drain valve 10 is lowered, the expansible-,contractible substance in the vthermostatic element 70 will contractand plunger 74 will move inwardly, which causes thefover-.all :length of theelement to be fless. The springs 42 and 56 will be acting 'to force the piston 44 toward the fleft, which will force the trigger member 60 in a 4 counter-clockwise direction as the thermostatic element becomes shorter. When the temperature of the surrounding air has been lowered to approximately 38, the thermostatic element will have shorted enough to allow trigger member 60 to be rotated so that notch 64 is above beveled edge 46.

This releases piston 44 and the entire valve mechanism moves forward impelled by spring 42 to the position shown in Fig. 5. Valve member 36 is forced away from valve seat 33 and is moved into .engagement with valve seat 35. As the sleeve 48 is carried forward byvalve stern 3'7, it carries cross pin 51 and piston 44 with it. When valve member 36-contacts valve seat 35, the spring 56 will abut against xed sleeve 4 8 and force piston 44 forward until cross pin 51 contacts the front edges of slots 54 and 55 in sleeve 48. Trigger member 60 will be held in the upward position by the thermostatic element 70.

With ,the valve mechanism moved to the drainage position as shown in Fig. 5, the water supply through nipple 27 will the -shut .,oif, and communication :between outlet V.chamber .25 and valve Achamber 24 is provided. The water fin condenser 12 will drain .through hose 13, passageway 29, `valve .chamber 24, outlet chamber 25, passageway 31, and those 77 into a suitable waste pipe. A `slot '78 .is provided in the upper portion .of valve chamber 24 which .connects with passageway 29 to insure rapid drainage of water .past :the valve .member 36. Since the :drain valve 10 is positioned below .the condenser 12, all the water will drain from :the condenser which will prevent damage to |the condenser as the temperature falls below 32. lf the temperature of the kthermostatic element "70 .is raised .above 38, it will return to its original length and trigger member A60 will be rotated clockwise with .notch 6.4 .protruding `into slot 47 of piston 44.

rValve Jbody 23 is provided with two bosses 79 and 80 to which an electric switch S1 is secured by bolts 82. A yswitch arm .83 =is secured to rod 84 which is connected to the lswitch i81. :Details of the switch are not shown since it can .beone of the vmany types on the market today. The arm 83 is 4held in .constant contact with `cross pin 51 by .any suitable means, -such as a spring. When the cross pin 5f1 .is moved forward .to drain position, the arm .83 is moved and rod 84 is rotated. This action closes the electric `switch 81 which completes an electric circuit to a relay 85 and an electric 4alarm bell 86 from a suitable power source through wire '87, switch 181, wire 88, relay coil 85, wire 89, .alarm ibell86, wire 90, and wire 91. The alarm be'll '86 will `begin to ring .which will warn an operator that the condenser 12 is approaching freezing conditions. As the y.relay is energized, arm 92 will be movedawayffrom contact 93 and the-current to motorcompressor unit 16 .wlill .be broken. This condition prevails until the operator cornes to investigate. If .the operator `wants to luse the air conditioner in the immediate future, he `may recock the 4valve mechanism by pulling to the right on the extended ends .of cross pin 51. As the cross pin 'is forced to the right, ,it carries sleeve 48 and .piston .44 -wit-h it so Lthat ltrigger `member 60 may be rotated until notch 64 is Vin engagement Vwith vbeveled edge 46. The thermostaticelement 70 `is warmed sufliciently to hold :the Itrigger member 60 in cocked position. The room must lthen =be warmed so that the valve does not again trip to the drain position. As the .cross pin 51 is pulled kto the right, arm 83 is rotated and the electric switch =81 is opened which breaks the circuit to the alarm bell 86 and .relayx85. As the relay is deenergized, contact arm 92. `will move into engagement with contact 93 and the circuit will be .completed -.to motor-compressor unit `through wire 94, arm '92, v'wire 95, motorcompressor 16, wire 96, and wire 91. If considerable time elapses before the operator investigates, the room may have warmed up so that trigger member 60 has been rotated by thermostatic telement 70with -lower portion 63 of handle 61 extending into notch 47 of vpiston 44. It is then necessary to lay a small bag of crushed ice on thermostatic element 70 to shorten it before cooking the mechanism to operating position.

From the foregoing description, it can be seen that a drain valve is provided which will automatically operate to drain water from a water cooled condenser when the condenser is subjected to freezing' temperatures. The valve may be easily checked to determine if all parts are free and in good working order by simply bumping the extended end of sleeve 48. The resultant squirt of water out of the drain hose 77 will also indicate that the water supply is normal. Switch arm 83 may be moved to the left once or twice a season to be sure that the alarm bell 86 works properly. Since the drain valve is accurately responsive to temperature changes, there is no danger that the water in the condenser will be frozen and the refrigeration system may be placed in an unheated room.

It is obvious that minor changes may be made in the form and construction of the invention Without departing from the material spirit thereof. It is not, therefore, desired to conne the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.

What is claimed is:

1. A valve for a water system comprising a valve body having a valve chamber and a drain passageway, a valve port positioned within said valve body between said valve chamber and said drain passageway, a valve stem extending through said valve port, a valve member secured to one end of said valve stem which is adapted to open and close said valve port, a sleeve secured to the opposite end of said valve stem, a piston slidably received in said valve body, said sleeve slidably received within said piston, a trigger member pivotally mounted to said valve body for engaging said piston, spring means interposed between said piston and said sleeve which forces said valve member to closed position when said trigger member engages said piston, a leg formed on said trigger member, retaining means formed in said valve body, said leg and said retaining means relatively positioned to permit mounting of a temperature responsive device therebetween for controlling the pivoting of said trigger member, and means for forcing said valve member to open position when said trigger member disengages said piston.

2. A drain valve for a water system comprising a valve body having a valve chamber and a drain passageway, a valve port positioned within said valve body between said valve chamber and said drain passageway, a valve stem extending through said valve port, a valve member secured to one end of said valve stem, a trigger member pivotally secured to said valve body and pivotable to cocked and uncocked positions, a leg formed on said trigger member7 retaining means formed in said valve body, said leg and said retaining means relatively positioned to permit mounting of a temperature responsive expansible and contractible element therebetween for maintaining said trigger member in the cocked position responsive to the expansion of said element and the uncocked position responsive to the contraction of said element, a piston slidably mounted in said valve body when said trigger member is uncocked, said trigger member cooperating with said piston in the cocked position to immobilize said piston, resilient means which cooperates-with said valve stem and said piston when said piston is immobilized for forcing said valve member to closed position, said resilient means being made inoperative when said piston is mobilized when said thermostatic element has rotated said trigger member to said uncocked position, and spring means for moving said valve member to open position when said resilient means is inoperative.

3. A valve for a water system comprising a valve body having a valve chamber and a drain passageway, a valve port positioned within said valve body between said valve chamber and said drain passageway, a valve stem extending through said valve port, a valve member secured to one end of said Valve stem which is adapted to open and close said `valve port, a sleeve secured to the opposite end of said valve stem, a piston slidably received in said valve body, said sleeve slidably received within said' piston, a trigger member for engaging said piston mounting means pivotally mounting said trigger member to said valve body, spring means interposed between said piston and said sleeve which forces said valve member to closed position when said trigger member engages said piston, a leg formed on said trigger member, biasing means formed in said leg, retaining means formed in said valve body, said biasing means and said retaining means relatively positioned and adjustable to permit mounting of a temperature responsive device therebetween for controlling and adjusting the pivoting of said trigger member to engage said piston, means for forcing said valve member to open position when said trigger member disengages said piston, and a cross pin secured to said piston for manually resetting said valve member to closed position.

4. A drain valve for a water system comprising a valve body having a valve chamber and a drain passageway, a valve port positioned within said valve body between said valve chamber and said drain passageway, a valve stem extending through said valve port, a valve member secured to one end of said valve stem, a trigger member pivotally secured to said valve body and pivotable to cocked and uncocked positions, a lever arm rigidly mounted to said trigger member, said lever arm and said retaining means relatively positioned to permit mounting of a temperature responsive expansible and contractible device therebetween for maintaining said trigger member in the cocked position responsive to the expansion of said device and the uncocked position responsive to the contraction of said device, a piston, means operating responsive to said trigger member when cocked for immobilizing said piston and operating responsive to said trigger member when uncocked for mobilizingI said piston,`re silient means operating responsive to the immobilization of said piston for forcing said valve member to closed position, said resilient means being made inoperative responsive to the mobilization of said piston, spring means for moving said valve member to open position when said resilient means is inoperative, and manual means for forcing said valve member to closed position and recocking said trigger member.

References Cited in the le of this patent UNITED STATES PATENTS 1,338,469 Waage et al, Apr. 27, 1920 1,786,878 Van Keuren Dec. 30, 1930 1,849,491 Kelley Mar. 15, 1932 1,874,106 Labbe Aug. 30, 1932 1,971,459 McGuire Aug. 28, 1934 2,214,844 Van Keuren Sept. 17, 1940 2,236,227 Wantz Mar. 25, 1941 2,301,876 Hurlburt Nov. 10, 1942 2,466,460 Marshall Apr. 5, 1949 2,487,852 Cook Nov. 15, 1949 FOREIGN PATENTS 372,965 Germany 1923 

